U.S. patent number 3,906,928 [Application Number 05/455,870] was granted by the patent office on 1975-09-23 for solar heater control system and method.
This patent grant is currently assigned to Fafco Incorporated. Invention is credited to Allen C. Wright.
United States Patent |
3,906,928 |
Wright |
September 23, 1975 |
Solar heater control system and method
Abstract
A pool water heating system used in conjunction with a pool pump
and filter wherein the pool water is directed along one of two
paths down stream of the filter. One path directs the filtered
water directly back to the pool and the other path directs the
filtered water through an array of heater panels for transferring
heat generated by solar energy to the water prior to returning it
to the pool. A solar heat sensor is positioned to sense the
temperature induced by solar energy in the location of the heater
panels and to provide an electrical signal which is connected to a
control valve. A flow direction valve is positioned in the direct
flow path to the pool which is urged to pinch off the flow
therethrough by pressure directed to a valve chamber therein.
Pressure at the filter inlet is directed to one port on the control
valve and an exhaust port on the control valve is connected to the
inlet side of the pump. When solar heat is available to heat the
pool water the solar heat sensor directs the control valve to
communicate the filter inlet pressure with the flow direction
valve, causing blockage of direct flow to the pool and flow through
the heater panels for heating prior to returning to the pool. When
solar heat is not available as determined by the solar heat sensor
the exhaust port on the control valve is communicated with the
pinch valve to bleed the valve chamber therein and allow filtered
water to flow directly therethrough to the pool.
Inventors: |
Wright; Allen C. (Moraga,
CA) |
Assignee: |
Fafco Incorporated (Redwood
City, CA)
|
Family
ID: |
23810580 |
Appl.
No.: |
05/455,870 |
Filed: |
March 28, 1974 |
Current U.S.
Class: |
126/563; 4/493;
126/586; 126/584; 126/592 |
Current CPC
Class: |
F24S
20/02 (20180501); F24S 50/40 (20180501); Y02E
10/40 (20130101) |
Current International
Class: |
F24J
2/42 (20060101); F24J 2/40 (20060101); F24J
003/02 () |
Field of
Search: |
;126/271 ;4/172.17
;232/1A ;210/169 ;251/5 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: O'Dea; William F.
Assistant Examiner: Ferguson; Peter D.
Attorney, Agent or Firm: Flehr, Hohbach, Test, Albritton
& Herbert
Claims
I claim:
1. In a system for controlling temperature in a confined body of
water having a system inlet and outlet in communication with the
body of water, a pump in communication with the inlet for moving
the water under pressure, a filter for receiving the water under
pressure and having an upstream pressure higher than a downstream
pressure, first and second parallel water paths for receiving the
water from the filter and being in communication with the system
outlet, an array of solar heater panels within the first water path
for passing water therethrough and for exchanging heat between the
heater panels and the passing water, means for sensing solar energy
positioned proximate to the heater panels for providing a control
signal related to available solar energy for raising the water
temperature above a predetermined temperature, means receiving said
control signal for controlling flow alternately in said first and
second water paths, a flow direction valve in the second water path
for controlling water flow therethrough, a pressure line connected
between said means for controlling and the upstream side of the
filter for communicating the prefilter pressure to said last named
means, and a control line connected between said means for
controlling and said flow direction valve, so that when said means
for sensing solar energy detects availability of solar energy for
raising water temperature above the predetermined temperature, said
control signal actuates said means for controlling to communicate
said pressure line with said control line, whereby said flow
direction valve is closed against filter downstream pressure by
filter upstream pressure, and the water is directed through the
first water path and said solar heater panels.
2. A system as in claim 1 wherein said solar heater panels in the
first water path are elevated relative to the second water path,
together with an exhaust line connected to said means for
controlling, so that when means for sensing detects insufficient
solar energy availability, said exhaust line is communicated with
said control line thereby relieving the pressure at said flow
direction valve and opening said flow direction valve so that water
flows through the second water path to the outlet as the path of
least resistance.
3. A system as in claim 1 together with means for interrupting said
control signal, and an exhaust port on said control valve, so that
when said means for interrupting is in one position said means for
controlling is isolated from said control signal and said last
named means may thereafter be positioned manually for alternately
communicating said pressure line and said exhaust port with said
control line, whereby manual closing and opening of said flow
direction valve is obtained respectively.
4. A system as in claim 1 together with an additional flow
direction valve in the first water path, an additional control line
connected between said means for controlling and said additional
flow direction valve, and an exhaust port on said control valve, so
that when said solar heat sensor senses availability of solar
energy for raising the water temperature above said predetermined
temperature, said exhaust port is placed in communication with said
additional control line, whereby said additional flow direction
valve is positively opened.
5. A system as in claim 4 together with an exhaust line connecting
the exhaust port to the inlet side of the pump, so that when said
control line and said additional control line are alternately
placed in communication with said exhaust port said flow direction
valve and said additional flow direction valve are alternately
positively opened by the low pressure at the pump inlet relative to
the pressure of the flow through said valves.
6. A system for heating the water in a swimming pool wherein the
system has an inlet from the pool and an outlet to the pool, a pump
in communication with the inlet, a filter for receiving the water
moved by the pump at the pump pressure, and first and second
parallel water paths for conducting the water from the filter and
returning the water to the outlet, comprising an array of heater
panels for absorbing solar energy, said array being positioned in
the first water path, means for sensing solar heat for exposure to
solar energy for providing an output signal related to a
predetermined solar energy induced temperature, means for
controlling connected to receive said output signal, an exhaust
port on said means for controlling, a flow direction valve
positioned in the second water path, a pressure line connected
between the pump outlet and said means for controlling, and a
control line connected between said means for controlling and said
flow direction valve, said means for controlling being actuated by
said output signal to communicate said pressure line with said
control line above said predetermined temperature, and said flow
direction valve being actuated closed by pressure directed through
said control line, whereby the second water path is blocked and
substantially all of the water is pumped through the first water
path and said array of heater panels for heating the water by
transfer of the absorbed solar energy thereto prior to returning
the water through the outlet to the pool.
7. A system as in claim 6 together with an exhaust line connected
to said exhaust port, wherein said exhaust line is connected to the
inlet side of the pump where a pre-pump pressure exists which is
lower than said pump pressure, whereby said flow direction valve is
positively opened when said output signal is indicative of a
temperature below said predetermined solar energy induced
temperature and said means for controlling communicates said
exhaust port with said control line.
8. A system as in claim 7 together with an additional flow
direction valve positioned in the first water path, and an
additional control line connected between said means for
controlling and said additional flow direction valve, said means
for controlling operating to place said pressure line in
communication with one of said control and additional control
lines, and to place said exhaust port in communication with the
other of said additional control and control lines respectively,
whereby one of said flow direction and additional flow direction
valves is positively closed and the other is positively opened.
9. A system as in claim 6 together with means for interrupting said
output signal connected between said means for sensing and said
means for controlling, whereby when said means for interrupting is
closed said flow direction valve is controlled by said means for
sensing, and when said means for interrupting is opened said flow
direction valve is controlled by manual actuation of said means for
controlling.
Description
BACKGROUND OF THE INVENTION
1. Field of the invention
The invention relates to a system for controlling temperature in a
confined body of water, and more particularly to a system for
automatically heating the water in a swimming pool using solar
energy and for cooling the swimming pool water through the use of a
manual control.
2. Description of the prior art
Heating systems for confined bodies of water such as swimming pools
generally utilize heat energy from burning gas or electric heater
elements. Installation, maintenance and operating costs for these
types of heater systems are considerable. The water is withdrawn
from the pools by a pump associated with a necessary pool water
filtering system and is subsequently passed through the heater
prior to return to the pool. A heating system for the pool water is
needed to either replace or supplement known pool heaters. The
replacement or supplementary heater, to be sufficientally
attractive, must draw heat energy from a source which will reduce
the operating costs normally associated with energy derived from
the public utilities.
There is therefore a need for a pool heating system utilizing
available solar energy which is relatively inexpensive to install,
maintain, and operate.
SUMMARY AND OBJECTS OF THE INVENTION
In general the system disclosed herein is used for controlling the
temperature in a confined body of water such as a swimming pool
having a pump and a filter associated therewith for removing
impurities from the water. Alternate paths exist down stream of the
filter, a direct path back to the pool and a path passing through
an array of solar heater panels prior to return to the pool. A heat
sensor is located to sense the solar energy available for heating
at the heater panels. A flow direction valve is positioned in the
direct return path to the pool having a control line connected
thereto which extends to a control valve. A pressure line extends
from a point upstresm of the filter to the control valve. The
control valve has an exhaust port which may be connected by an
exhaust line to the inlet side of the pump. The heat sensor
provides a signal to the control valve which communicates the
pressure line to the flow direction valve when solar energy is
available at the heater panels sufficient to raise the water
temperature above a predetermined temperature. In like manner the
heat sensor communicates the exhaust port on the control valve with
the flow direction valve when insufficient solar energy is
available at the heater panels to raise the water above the
predetermined temperature.
In general it is an object of the present invention to provide a
system for controlling temperature in a confined body of water
which utilizes existing filter system water pressures for
controlling the route of water flow through the system.
It is another object of the present invention to provide a system
for controlling temperature in a confined body of water which uses
only one pressure control valve for blocking a preferred flow path
thereby directing the flow through an elevated array of solar
heater panels.
Another object of the present invention is to provide a system for
controlling temperature in a confined body of water which utilizes
water pressure taken from the upstream side of an existing filter
for controlling selection of return flow path downstream of the
filter to the body of water.
It is another object of the present invention to provide a system
for controlling temperature in a confined body of water having
pressure controlled flow direction valves in each of two return
paths downstream of the filter which are alternately controlled
between open and closed position by a control valve receiving
control pressure from a point upstream of the filter.
It is another object of the present invention to provide a system
for controlling temperature in a confined body of water which may
be manually operated to direct flow through an array of solar
heater panels to cool the water when the solar energy available is
below that required to rise the temperature of the water.
Another object of the present invention is to provide a system for
controlling temperature in a confined body of water wherein the
pressure controlled flow direction valve is positively opened by
control pressure after being in a closed position.
Additional objects and features of the invention will appear from
the following description in which the preferred embodiment has
been set forth in detail in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the system in which the solar heater
panels are elevated relative to the direct return path to the
pool.
FIG. 2 is a block diagram of the system in which the solar heater
panels may occupy any elevation relative to the direct return path
to the pool.
FIG. 3 is an electrical and hydraulic schematic of one practical
embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The temperature within a confined body of water may be controlled
using heating panels which are disposed in the environment
surrounding the body of water. One such practical use for a system
based on this principle is a system associated with a swimming pool
for controlling the temperature of the water in the pool. In the
majority of instances it is desired to elevate the temperature of
the water in the pool, although there are times when it may be
desirable to reduce the temperature of the water in the pool. For
either purpose a system associated with a swimming pool such as
that shown in FIG. 1 may be used. An inlet from the pool to the
system is shown at the left of FIG. 1, through which water is drawn
by the action of a pump 11 which provides water pressure to the
inlet of a filter 12. Downstream of filter 12 two return paths may
be seen. One path is a direct return path 13 in which a flow
direction valve 14 is situated and an alternate path is provided by
indirect return path 16 in which is positioned an array of solar
heating panels 17.
A solar heat sensor 18 is positioned so as to sense the
availability of solar energy for providing heat to the array of
heater panels 17. It is usual that solar heat sensor 18 is situated
proximate to heater panels 17 as indicated by dashed lines 19 so
that the actual solar energy available at the location of heater
panels 17 is sensed.
Solar heat sensor 18 provides an output signal or control signal
which is electrically connected to a control valve 21. A mode
control switch 22 may be provided to interrupt the connection for
the control signal from sensor 18, so that the control valve 21 bay
be operated in either an automatic mode or a manual mode. When
switch 22 is in the manual position the electrical circuit from
solar heat sensor 18 to control valve 21 is open, and actuation of
control valve 21 must be by manual means. Control valve 21 has the
pressure at the inlet to filter 12 connected thereto through a
pressure line 23. A control line 24 is connected between control
valve 21 and flow direction valve 14. Control valve 21 has an
exhaust port 26 to which may be connected an exhaust line 27
extending to the inlet side of pump 11. It may be seen by reference
to FIG. 1 that water leaving solar heater panels 17 or passing flow
direction valve 14 continues through the remainder of indirect and
direct return paths 16 and 13 respectively to the system outlet to
the pool as marked at the right side of FIG. 1.
Ths system of FIG. 1 controls the temperature in a confined body of
water, such as that within a swimming pool, in the following
fashion in one embodiment. Heater panels 17 and indirect return
path 16 are elevated to some degree above direct return path 13.
Flow direction valve 14 may be of the "pinch" type as disclosed in
copending patent application, Ser. No. 455,869 filed March 28,
1974. As may be seen therein, flow direction valve 14 contains a
valve chamber and a pressure port for communicating pressure to the
valve chamber. When pressure is introduced to the valve chamber in
flow direction valve 14 a flexible member forming one wall of the
valve chamber distends inwardly to block the flow through the
valve.
With switch 22 in the automatic position (closed) solar heat sensor
18 is set to provide a control signal at a predetermined solar
energy level which initiates flow through heating panels 17 thereby
transferring heat to water flowing therethrough. The control signal
is connected to control valve 21 which communicates pressure line
23 with control line 24 thereby providing pressure to the pressure
port of flow direction valve 14. Flow direction valve 14 closes, as
described above, blocking flow through direct return path 13
thereby causing the flow from filter 12 to be diverted to indirect
return path 16 and through heater panels 17. Heat transferred from
heater panels 17 to the water flowing therethrough raises the
temperature of the water which is subsequentally returned to the
pool through the remainder of indirect return path 16 and the
system outlet.
When solar heat sensor 18 detects an insufficient level of solar
energy for raising the water in the pool above a predetermined
temperature. Control valve 21 is returned to a position whereby
control line 24 is placed in communication with exhaust port 26.
Pressure in the valve chamber of flow direction valve 14 is bled
off through control line 24 and exhaust port 26. Means may be
provided in the form of exhaust line 27 between exhaust port 26 and
the inlet side of pump 11 for positively opening flow direction
valve 14 by providing a low pressure to the valve chamber, thereby
positively bleeding off the pressure from the valve chamber. Flow
direction valve 14 now being in an open condition, the flow from
the outlet of filter 12 follows the preferred lower level direct
return path 13 to the system outlet to the pool.
In the event it is desired to use the system of FIG. 1 to reduce
the temperature of the pool water, switch 22 may be positioned to
the manual position. Control valve 21 may now be manually
positioned to communicate pressure line 23 with control line 24
closing flow direction vlave 14. As described above the flow at the
output of filter 12 is diverted through indirect path 16 and heater
panels 17 whereupon it is returned to the pool. If there is
insufficient solar energy available to raise the temperature of the
water passing through the panels 17 above the predetermined
temperature then heat exchange occurs in the opposite direction and
the heater panels 17 remove heat energy form the pool water flowing
therethrough and pass it to the surrounding environment. The water
returns through indirect return path 16 to the pool at a
temperature lower than the temperature at which it was drawn from
the pool by pump 11. In this fashion the water in the pool may be
reduced in temperature to an equlibrium temperature with the
environment surrounding heater panels 17.
Referring to FIG. 2 a block diagram is shown of a system for
controlling temperature in a confined body of water, such as that
contained in a swimming pool, where the heater panels 17 may not be
in a position which is elevated relative to the direct return path
13. Items in FIG. 2 which are direct counterparts of items in FIG.
1 are given identical item numbers. The distinctions in FIG. 2, as
compared to that of FIG. 1, lie in the insertion of an additional
flow direction valve 28 in indirect return path 16, a four-way
control valve 29 which replaces control vlave 21, and an additional
control line 31 which extends between additional flow direction
valve 28 and four-way control valve 29.
Since the relative elevations of direct return path 13 and indirect
return path 16 no longer provide for a preferred return through
direct path 13, additional flow direction valve 28 becomes
necessary. Four-way control valve 29 is configured to alternately
connect exhaust port 26 to control line 24 and pressure line 23 to
additional control line 31, and exhaust port 26 to additional
control line 31 and pressure line 23 to control line 24. When
switch 22 is in the closed or automatic position and solar heat
sensor 18 determines that an insufficient level of solar energy is
available to raise the pool water above the predetermined
temperature, four-way control valve 29 is in the first mentioned
position. Thus, flow direction valve 14 is open and additional flow
direction valve 28 is closed, whereby filtered water returns to the
pool through direct flow path 13. When solar heat sensor 18 detects
availability of a sufficient level of solar energy to raise the
temperature of the pool water above the predetermined temperature,
four-way control valve 29 is urged to the last mentioned position
thereby closing flow direction valve 14 and opening additional flow
direction vlave 28. Filtered water is then directed through
indirect return path 16, through heater panels 17 to receive heat
transferred therefrom, and returned to the pool.
FIG. 3 is a practical embodiment of the system shown in FIG. 2 and
therefore shows all of the necessary elements for a practical
embodiment of the system shown in FIG. 1. In FIG. 3 a control box,
shown generally at 32, contains an on-off switch S1 for connecting
an AC power input to the system. The circuit is fused by a fuse F1.
A transformer 33 is shown for providing power to an actuating coil
34 for four-way control valve 29. Solar heat sensor 18 is shown in
one embodiment as a thermal switch 36 located proximate to the
array of heater panels 17. Switch S2 in control box 32 performs the
function of switch 22 in FIGS. 1 and 2. Switch S2 in the closed
condition is equivalent to switch 22 in the open or manual
position. Conversely switch S2 in the open condition is equivalent
to switch 22 in the closed or automatic position. The operation of
the system shown in FIG. 3 involves closing switch S1 to place the
system in a ready condition. Depending upon whether manual or
automatic operation is desired switch S2 is either closed or opened
respectively. The remainder of the operation of the system shown in
FIG. 3 is the same as that described for the operation of the
system shown in FIG. 2 above.
A method for controlling temperature in a confined body of water
such as a swimming pool, involves pumping water from the pool and
filtering the water. The method further involves diverting the
water downstream of the filter through one of two alternate return
paths to the pool. Collecting available solar heat is performed in
the heating panels. Sensing of an available solar energy level
sufficient to provide heat for transfer to the circulated pool
water is performed. The method includes routing the filtered water
through the path for receiving heat energy from the environmnet
when sufficient solar energy availability is sensed, and routing
the filtered water directly back to the pool when insuffient
availability of solar energy is sensed. The routing of the filtered
flow is obtained by connecting pressure upstream of the filter to
an appropriate flow direction valve for blocking or opening the
appropriate return path to the pool as determined in the solar
energy level determination step. The method also includes positive
opening of flow direction valves previously closed by introducing a
low pressure from a point upstream of the pump to the previously
closed valve.
A system and method has been diclosed for controlling temperature
in a confined body of water such as that contained in a swimming
pool which may be operated manually or automatically. This system
and method includes allowance for elevating the temperature of the
water above a predetermined temperature and for lowering the
temperature of the water to a temperature of equlibrium with the
surrounding environment. The system may be used to supplement a
conventional pool heating system by directing the system outlet to
the conventional heating system inlet prior to return to the pool.
The system provides a replacement or supplementary heating system
for conventional pool heating systems and requires comparatively
low installation, maintenance and operating costs.
* * * * *